30 December 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a portion of an old impact crater that was filled, buried, and is now being exhumed from within sedimentary rock strata located in western Arabia Terra, the region immediately north of Meridiani Planum. The Mars Exploration Rover, Opportunity, has explored sedimentary rocks in the Meridiani region; the rocks of nearby western Arabia can only be explored (for the time being) from orbit. Wind has sculpted some of the layered rock into streamlined forms known as yardangs. The crater shown here, at one time, may have been the site of a small lake. The crater is located near 8.4N, 5.7W. The picture covers an area about 3 km (1.9 mi) across and is illuminated by sunlight from the upper left.